Plate Heat Exchanger

ABSTRACT

A plate heat exchanger includes a first plate sheet and a second plate sheet. A blocking member is disposed between a front surface of the second plate sheet and a back surface of the first plate sheet. The blocking member is located between a first corner hole and a second corner hole of the second plate sheet, and one end of the blocking member is located on a side portion of the second plate sheet. A first corner hole of the second plate sheet bypasses the other end of the blocking member to communicate with a second corner hole of the second plate sheet. In the plate heat exchanger, a blocking member is disposed between two plate sheets, accordingly fluid can be evenly distributed, and the plate heat exchanger has good heat exchange performance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority to Chinese Patent Application No.201610733702.X titled “PLATE HEAT EXCHANGER”, filed with China NationalIntellectual Property Administration on Aug. 25, 2016, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates to a heat exchange device, and inparticular to a plate heat exchanger.

BACKGROUND OF THE INVENTION

A plate heat exchanger is a compact and efficient heat exchanger, whichis widely used in power, chemical, air conditioning and otherindustries, and it is also a key device in new energy applications suchas waste heat utilization. In the air conditioning system, the plateheat exchanger is usually used as an evaporator and a condenser. In thenew energy automobile, the plate heat exchanger is used in the batterythermal management system for performing heat exchange between therefrigerant and the cooling liquid.

Generally, according to different positions of the inlet and outlet ofthe refrigerant, the plate heat exchanger may be classified into twotypes, one type is that the inlet and outlet of the refrigerant are atdifferent sides, which is called a “diagonal flow” plate heat exchanger,and the other type is that the inlet and outlet of the refrigerant areat the same side, which is called an “unilateral flow” plate heatexchanger. In some special working conditions, the size, volume andweight of the plate heat exchanger are limited, especially inautomobiles. For some small-sized plate heat exchangers, the flow of therefrigerant is apt to be unevenly distributed due to the short passageof the refrigerant, and the uneven flow distribution may result in lowerheat exchange efficiency.

Therefore, a technical problem to be addresses is to provide a heatexchange device with uniform flow distribution and good heat exchangeperformance.

SUMMARY OF THE INVENTION

In order to solve the above technical problem, the following technicalsolution is adopted in the present application. A plate heat exchangerincludes a heat exchange core, and a first flow passage and a secondflow passage isolated from each other are formed in the heat exchangecore. The heat exchange core includes first plates and second plates.Each of the first plates includes a front surface at a side facing anadjacent second plate, and a back surface at another side opposite tothe front surface. Each of the second plates includes a front surface ata side facing an adjacent first plate, and a back surface at anotherside opposite to the front surface. Portions of the second flow passageare formed between the front surfaces of the first plates and the backsurfaces of the adjacent second plates, and portions of the first flowpassage are formed between the front surfaces of the second plates andthe back surfaces of the adjacent first plates. The first plate includesa first corner hole, a second corner hole, a third corner hole and afourth corner hole, the second plate also includes a first corner hole,a second corner hole, a third corner hole and a fourth corner hole, andthe first corner hole, the second corner hole, the third corner hole andthe fourth corner hole of the first plate are arranged to correspond tothe first corner hole, the second corner hole, the third corner hole andthe fourth corner hole of the first plate, respectively.

The first corner hole and the second corner hole of the second plate arein communication with each other, and a blocking member is arrangedbetween the front surface of the second plate and the back surface ofthe first plate. The blocking member is located between the first cornerhole and the second corner hole of the second plate. One end of theblocking member is located at a side portion of the heat exchange core,and the first corner hole of the second plate bypasses another end ofthe blocking member to communicate with the second corner hole of thesecond plate.

According to the plate heat exchanger of the present application, byproviding the blocking member between the front surface of the secondplate and the back surface of the first plate, the fluid can be evenlydistributed, so that the plate heat exchanger has better heat exchangeperformance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective structural view of an embodiment of a plate heatexchanger according to the present application;

FIG. 2 is a partial exploded view of a heat exchange core of the plateheat exchanger shown in FIG. 1;

FIG. 3 is a schematic view showing the structure of a second plate ofthe plate heat exchanger shown in FIG. 1;

FIG. 4 is a schematic view showing the structure of a second fin of theplate heat exchanger shown in FIG. 1, in which for the sake of clarity,only a part of the fin structure is shown;

FIG. 5 is a schematic view showing the structure of a baffle of theplate heat exchanger shown in FIG. 1;

FIG. 6 is a structural schematic view showing an assembly of the secondplate, the second fin and the baffle of the plate heat exchanger shownin FIG. 1, where arrows indicate the flow directions of a fluid;

FIG. 7 is a structural schematic view showing an assembly of a secondplate, a second fin and a baffle of a plate heat exchanger according toanother embodiment of the present application;

FIG. 8 is a structural schematic view showing an assembly of a secondplate, a second fin and a baffle of a plate heat exchanger according toyet another embodiment of the present application; and

FIG. 9 is a structural schematic view showing an assembly of a secondplate, a second fin and a baffle of a plate heat exchanger according tostill another embodiment of the present application.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, specific embodiments of the present application will beillustrated in detail in conjunction with accompanying drawings.

FIG. 1 is a perspective structural view of a plate heat exchangeraccording to the present application. As shown, the plate heat exchangerincludes a heat exchange core 1, and a first flow passage and a secondflow passage isolated from each other are formed in the heat exchangecore. The plate heat exchanger further includes an adapting block 2, andthe adapting block 2 is provided with a first connecting opening 21 anda second connecting opening 22, wherein both the first connectingopening 21 and the second connecting opening 22 are in communicationwith the first flow passage, and the first connecting opening 21 is incommunication with the second connecting opening 2 through the firstflow passage. The plate heat exchanger further includes a thirdconnecting opening 3 and a fourth connecting opening 4, both the thirdconnecting opening 3 and the fourth connecting opening 4 are incommunication with the second flow passage, and the third connectingopening 3 is in communication with the fourth connecting opening 4through the second flow passage. It should be clarified herein that theplate heat exchanger may not be provided with the adapting block 2, butbe provided with a first connecting opening and a second connectingopening as the third connecting opening and the fourth connectingopening. In this embodiment, by providing the adapting block, a distancebetween the first connecting opening and the second connecting openingcan be set as needed, so as to facilitate the installation of the plateheat exchanger and a throttle element (not shown in the figure).

As shown in FIG. 2, the heat exchange core 1 includes first plates 11,second plates 12, first fins 13, second fins 14, and baffles 15. Each ofthe first fins 13 is arranged between a front surface 110 of acorresponding first plate 11 and a back surface of a correspondingsecond plate 12, and each of the second fins 14 and each of the baffles15 are arranged between a front surface 120 of a corresponding secondplate 12 and a back surface of a corresponding first plate 11. Portionsof the second flow passage are formed between front surfaces 110 of thefirst plates 11 and back surfaces of the second plates 12, and portionsof the first flow passage are formed between front surfaces 120 of thesecond plates 12 and back surfaces of the first plates 11. In thisembodiment, the first plate 11 and the second plate 12 may be obtainedby horizontally rotating a same plate by 180 degrees, of course, thefirst plate 11 and the second plate 12 may also be two plates ofdifferent structures. Moreover, the number of the portions of the secondflow passage formed between the front surfaces 110 of the first plates11 and the back surfaces of the second plates 12 is n1, and the numberof the portions of the first flow passage formed between the frontsurfaces 120 of the second plates 12 and the back surfaces of the firstplates 11 is n2, n2 is greater than n1, and n2−n1=1.

The plates of this embodiment are illustrated hereinafter by taking thesecond plate 12 as an example. As shown in FIG. 3, the second plate 12includes a plate plane 125, and a first corner hole 121, a second cornerhole 122, a third corner hole 123 and a fourth corner hole 124 which arelocated at four corners of the plate plane 125, respectively. The secondplate 12 further includes a flanging structure 126 enclosing the plateplane 125. The flanging structure 126 protrudes from the plate plane 125by a certain distance. Herein, one side surface of the second plate 12enclosed by the flanging structure 126 is defined as the back surface ofthe second plate 12, and the other side surface opposite to the backsurface is defined as the front surface of the second plate 12.Circumferential sides of the third corner hole 123 and the fourth cornerhole 124 are formed with annular bosses protruding from the plate plane125 by a certain distance. Thus, in a case that the first plate 11 andthe second plate 12 are stacked together, the annular bosses formed atthe circumferential sides of the third corner hole 123 and the fourthcorner hole 124 at the front surface 120 of the second plate 12 are incontact with a plate plane of the back surface of the first plate 11,such that the third corner hole 123 and the fourth corner hole 124 areisolated from the first flow passage formed between the front surface120 of the second plate 12 and the back surface of the first plate 11.The structure of the first plate 11 is similar to that of the secondplate 12, which will not be described herein.

FIG. 4 is a schematic view showing the structure of the second fin 14.In order to clearly show the structure of the fin, the fin structure isonly shown in a partial region of the figure, and is not shown in otherregions.

As shown in FIG. 4, the second fin 14 includes a first hole 141, asecond hole 142, a third hole 143, and a fourth hole 144 located at fourcorners, the first hole 141, the second hole 142, the third hole 143 andthe fourth hole 144 of the second fin 14 correspond to the first cornerhole 121, the second corner hole 122, the third corner hole 123 and thefourth corner hole 124 of the second plate 12, respectively. Innerdiameters of the third hole 143 and the fourth hole 144 are larger thaninner diameters of the third corner hole 123 and the fourth corner hole124, so that the third hole 143 and the fourth hole 144 can be sleevedon the annular bosses formed at the circumferential sides of the thirdcorner hole 123 and the fourth corner hole 124 respectively.

The second fin 14 is further provided with a notch 145. The notch 145 islocated between the first hole 141 and the second hole 142, and thenotch 145 extends from a side close to the first hole 141 and the secondhole 142 of the second fin 14 to an opposite side. As shown in thefigure, a length of a fin region between the first hole 141 and thesecond hole 142 is L2, and a length of a fin region between the firsthole 141 and the notch 145 is L1. L1 and L2 satisfy: ¼≤L1/L2≤¾. L1 ishalf of L2 in this embodiment. A width of the notch 145 is B1, and awidth of the second fin 14 is B2. B1 and B2 satisfy: ¼≤B1/B2≤¾, or¼≤B1/B2≤½. B1 is half of B2 in this embodiment.

FIG. 5 shows the structure of the baffle 15. The baffle 15 may be madeof a metal material. A size of the baffle 15 matches with a size of thenotch 145, and the baffle 15 and the notch 145 may be in a clearancefit. Surfaces of the baffle 15 and the notch 145 are provided with acomposite layer for welding. A height of the baffle 15, a height of thesecond fin 14 and heights of the annular bosses formed at thecircumferential sides of the third corner hole 123 and the fourth cornerhole 124 of the second plate 12 are substantially the same, whichfacilitates improving the stability of the welding.

The first fin 13 differs from the second fin 14 mainly in that no notchis provided at the first fin 13. The fin structures (for example, alouver size) of the first fin 13 and the second fin 14 may be the sameor different. The fin structure is determined by a refrigerant in theflow passages, which will not be described in detail herein. Otherstructures of the first fin 13 may be the same as or similar to that ofthe second fin 14, which will not be described herein.

FIG. 6 is a structural schematic view showing an assembly of the secondplate 12, the second fin 14 and the baffle 15, and the second plate 12,the second fin 14 and the baffle 15 may be welded together by brazing orthe like.

As shown in FIG. 6, the refrigerant first flows from the first cornerhole 121 into the portions of the first flow passage located between theback surface of the first plate 11 and the front surface of the secondplate 12, and then flows to the second corner hole 122 in a directionindicated by arrows. Since the baffle 15 is provided, a region in whicha distance between the first corner hole 121 and the second corner hole122 is short is blocked by the baffle 15, and the refrigerant isrequired to bypass the baffle 15 to flow to the second corner hole 122.In this way, the difference between lengths of flow paths in regions ofthe plate plane of the second plate 12 when the refrigerant flows fromthe first corner hole 121 to the second corner hole 122 may be reduced,besides, more refrigerant passes through a left side region of the plateplane and flows to the second corner hole 122, while a region of theback surface of the second plate 12 opposite to the left side region hasmore cooling liquid, thus a big heat exchange temperature difference isformed between the refrigerant and the cooling liquid, and therebyimproving the heat exchange performance.

Moreover, when the cooling liquid flows from the third corner hole tothe fourth corner hole, a temperature of the cooling liquid around thethird corner hole is relatively high. Since the baffle 15 is provided,more refrigerant is allowed to flow around the third corner hole, sothat heat of the cooling liquid can be fully adsorbed, and thus furtherensuring a superheat degree of the refrigerant.

The problem of uneven distribution of the refrigerant in the first flowpassage can be effectively solved according to this embodiment. In acase that a length of the plate heat exchanger is short, for example, aratio of a length to a width of the plate heat exchanger is in a rangeof 0.7 to 2, the heat exchange performance can be effectively improved.

It should be noted that, a baffle may also be provided between the frontsurface of the first plate 11 and the back surface of the second plate12, which will not be described herein.

FIG. 7 shows another embodiment of the present application. What isdifferent from the above embodiment is that, in this embodiment, nobaffle is arranged between the back surface of the first plate and thefront surface of the second plate. A rib 126 protruding from the frontsurface of the second plate 12 by a certain distance is formed on thesecond plate 12 by stamping. The rib 126 protrudes from the frontsurface of the second plate 12 by a height substantially equal to theheight of the second fin 14. By replacing the baffle 15 in the aboveembodiment with the rib 126 of an integral structure, the structure ofthe plate heat exchanger is simple, and the processing and installationare convenient; besides, the rib can better cooperate with the fin.

Other structures and features of this embodiment are the same as orsimilar to those of the above embodiment, which will not be describedherein.

FIG. 8 shows yet another embodiment of the present application. What isdifferent from the above embodiments is that, in this embodiment, thefirst corner hole 121, the third corner hole 123 and the fourth cornerhole 124 of the second plate 12 are located at three of the four cornersof the second plate 12, respectively, and the third corner hole 123 andthe fourth corner hole 124 are located at two opposite corners. Thesecond corner hole 122 is located between the first corner hole 121 andthe third corner hole 123. An arc-shaped baffle 15′ is further arrangedbetween the first corner hole 121 and the second corner hole 122, andone end of the baffle 15′ is close to a corner of the second plate 12where no corner hole is provided. In this way, during the fluid flowingfrom the first corner hole 121 to the second corner hole 122, the fluidcan flow around sufficiently, so that the flow path of the fluid is longenough, which avoids uneven fluid distribution due to a too shortdistance between the first corner hole 121 and the second corner hole122, and thereby improving the heat exchange performance. Moreover, inthis embodiment, the distance between the first corner hole 121 and thesecond corner hole 122 is short, which facilitates adjusting thedistance between the first corner hole 121 and the second corner hole122. Besides, in a case that the first connecting opening 21 and thesecond connecting opening 22 corresponding to the first corner hole 121and the second corner hole 122 respectively are mounted to expansionvalves, since a distance between the first connecting opening 21 and thesecond connecting opening 22 can be adjusted to correspond to connectingopenings of the expansion valves, the structure of the adapting blockmay be relatively simple, and the expansion valves can be directlymounted to the plate heat exchanger in an easier manner.

It should be noted that, the baffle 15′ may also be of a rib structureformed by stamping. Other structures of this embodiment are the same asor similar to those of the above embodiments, which will not bedescribed herein.

FIG. 9 shows still another embodiment of the present application. Whatis different from the above embodiments is that, in this embodiment, afin structure is not provided, while a concave-convex structure 117formed by stamping is provided in the first plate 11, a concave-convexstructure 127 formed by stamping is also provided in the second plate12, a rib 126 formed by stamping is further arranged at the second plate12, and the rib 126 and the concave-convex structure 127 may be formedby a same processing step. A plane portion 128 is arranged at a portionof the first plate 11 corresponding to the rib 126. By providing theplane portion 128, on the one hand, flow resistance in the region wherea distance between the third corner hole and the fourth corner hole ofthe first plate 11 is relatively long may be reduced, so that the fluidcan be evenly distributed, on the other hand, the rib 126 can bettercooperate with the back surface of the first plate 11.

It should be noted that, a baffle may be provided instead of the rib,and a portion where the rib is arranged is provided with a planestructure cooperating with the baffle. Other structures and features ofthis embodiment are the same as or similar to those of the aboveembodiments, which will not be described herein.

The embodiments described hereinabove are only specific embodiments ofthe present application, rather than limitation of the presentapplication in any form. Although the present application is disclosedby the above preferred embodiments, the preferred embodiments should notbe interpreted as a limitation to the present application. For thoseskilled in the art, many variations, modifications or equivalentreplacements may be made to the technical solutions of the presentapplication by using the methods and technical contents disclosedhereinabove, without departing from the scope of the technical solutionsof the present application. Therefore, any simple modifications,equivalent replacements and modifications, made to the above embodimentsbased on the technical essences of the present application withoutdeparting from the technical solutions of the present application, aredeemed to fall into the scope of the technical solution of the presentapplication.

1. A plate heat exchanger, comprising a heat exchange core, and a firstflow passage and a second flow passage isolated from each other beingformed in the heat exchange core, wherein the heat exchange corecomprises first plates and second plates, each of the first platescomprises a front surface and a back surface at an opposite side of thefront surface, and each of the second plates comprises a front surfaceand a back surface at an opposite side of the front surface; portions ofthe second flow passage are formed between the front surfaces of thefirst plates and the back surfaces of the adjacent second plates, andportions of the first flow passage are formed between the front surfacesof the second plates and the back surfaces of the adjacent first plates;the first plate comprises a first corner hole, a second corner hole, athird corner hole and a fourth corner hole, and the second plate alsocomprises a first corner hole, a second corner hole, a third corner holeand a fourth corner hole; the first corner hole, the second corner hole,the third corner hole and the fourth corner hole of the first plate arearranged to correspond to the first corner hole, the second corner hole,the third corner hole and the fourth corner hole of the second plate,respectively; and the first corner hole and the second corner hole ofthe second plate are in communication with each other, a blocking memberis arranged between the front surface of the second plate and the backsurface of the first plate, the blocking member is located between thefirst corner hole and the second corner hole of the second plate, oneend of the blocking member is located at a side portion of the heatexchange core, and the first corner hole of the second plate is incommunication with the second corner hole of the second plate byrounding another end of the blocking member.
 2. The plate heat exchangeraccording to claim 1, wherein the heat exchange core further comprisesfins, and each of the fins is arranged between the front surface of thesecond plate and the back surface of the corresponding first plate; eachof the fins comprises a first hole, a second hole, a third hole, and afourth hole; the first hole, the second hole, the third hole and thefourth hole of the fin correspond to the first corner hole, the secondcorner hole, the third corner hole and the fourth corner hole of thesecond plate, respectively; and the fin is further provided with anotch, the notch is located between the first hole and the second hole,the notch extends from a side close to the first hole and the secondhole to an opposite side; the blocking member is arranged at the notch,and the notch is in a clearance fit with the blocking member.
 3. Theplate heat exchanger according to claim 2, wherein the first cornerhole, the second corner hole, the third corner hole and the fourthcorner hole of the second plate are located at four corners of thesecond plate respectively; the first corner hole and the second cornerhole of the second plate are located at a same side, and the thirdcorner hole and the fourth corner hole of the second plate are locatedat a same side; the first corner hole and the third corner hole of thesecond plate are diagonally arranged, and the second corner hole and thefourth corner hole of the second plate are diagonally arranged; and thefirst hole, the second hole, the third hole and the fourth hole of thefin are also located at four corners of the fin, a length of a finregion between the first hole and the second hole is L2, a length of afin region between the first hole and the notch is L1, and L1 and L2satisfy: ¼≤L1/L2≤¾; and, a width of the notch is B1, a width of the finis B2, and B1 and B2 satisfy: ¼≤B1/B2≤¾.
 4. The plate heat exchangeraccording to claim 3, wherein the blocking member is a baffle, the fin,the baffle and the second plate are fixed together by welding, L1 ishalf of L2, and ¼≤B1/B2≤½.
 5. The plate heat exchanger according toclaim 1, wherein the first corner hole, the third corner hole and thefourth corner hole of the second plate are located at three of the fourcorners of the second plate, respectively, and the third corner hole andthe fourth corner hole are diagonally arranged; and the second cornerhole is located between the first corner hole and the third corner hole,the blocking member is of an arc-shaped or irregular structure, and oneend of the blocking member is close to a corner of the second platewhere no corner hole is provided.
 6. The plate heat exchanger accordingto claim 5, wherein the blocking member is a baffle, and the baffle andthe second plate are fixed together by welding.
 7. The plate heatexchanger according to claim 1, wherein the blocking member is a ribprotruding from the front surface of the second plate by a certaindistance, the second plate is stamped to form the rib, and the rib andthe second plate are integrated.
 8. The plate heat exchanger accordingto claim 1, wherein the number of the portions of the second flowpassage formed between the front surfaces of the first plates and theback surfaces of the second plates is n1, the number of the portions ofthe first flow passage formed between the front surfaces of the secondplates and the back surfaces of the first plates is n2, and n2 isgreater than n1.
 9. The plate heat exchanger according to claim 1,wherein both the first plate and the second plate are provided with aconcave-convex structure formed by stamping, a portion of the firstplate corresponding to the blocking member is provided with a planeportion, and/or a portion of the second plate corresponding to theblocking member is provided with a plane portion, and, the blockingmember and the plane portion of the first plate and/or the plane portionof the second plate are fixed together by welding.
 10. The plate heatexchanger according to claim 1, wherein a blocking member is furtherarranged between the front surface of the first plate and the backsurface of the second plate, the blocking member between the frontsurface of the first plate and the back surface of the second plate islocated between the third corner hole and the fourth corner hole of thefirst plate, one end of the blocking member between the front surface ofthe first plate and the back surface of the second plate is located at aside portion of the heat exchange core, and the third corner hole of thefirst plate bypasses another end of the blocking member between thefront surface of the first plate and the back surface of the secondplate to communicate with the fourth corner hole of the first plate. 11.The plate heat exchanger according to claim 2, wherein the first cornerhole, the third corner hole and the fourth corner hole of the secondplate are located at three of the four corners of the second plate,respectively, and the third corner hole and the fourth corner hole arediagonally arranged; and the second corner hole is located between thefirst corner hole and the third corner hole, the blocking member is ofan arc-shaped or irregular structure, and one end of the blocking memberis close to a corner of the second plate where no corner hole isprovided.
 12. The plate heat exchanger according to claim 2, wherein theblocking member is a rib protruding from the front surface of the secondplate by a certain distance, the second plate is stamped to form therib, and the rib and the second plate are integrated.
 13. The plate heatexchanger according to claim 3, wherein the blocking member is a ribprotruding from the front surface of the second plate by a certaindistance, the second plate is stamped to form the rib, and the rib andthe second plate are integrated.
 14. The plate heat exchanger accordingto claim 5, wherein the blocking member is a rib protruding from thefront surface of the second plate by a certain distance, the secondplate is stamped to form the rib, and the rib and the second plate areintegrated.
 15. The plate heat exchanger according to claim 11, whereinthe blocking member is a rib protruding from the front surface of thesecond plate by a certain distance, the second plate is stamped to formthe rib, and the rib and the second plate are integrated.
 16. The plateheat exchanger according to claim 2, wherein a blocking member isfurther arranged between the front surface of the first plate and theback surface of the second plate, the blocking member between the frontsurface of the first plate and the back surface of the second plate islocated between the third corner hole and the fourth corner hole of thefirst plate, one end of the blocking member between the front surface ofthe first plate and the back surface of the second plate is located at aside portion of the heat exchange core, and the third corner hole of thefirst plate bypasses another end of the blocking member between thefront surface of the first plate and the back surface of the secondplate to communicate with the fourth corner hole of the first plate. 17.The plate heat exchanger according to claim 3, wherein a blocking memberis further arranged between the front surface of the first plate and theback surface of the second plate, the blocking member between the frontsurface of the first plate and the back surface of the second plate islocated between the third corner hole and the fourth corner hole of thefirst plate, one end of the blocking member between the front surface ofthe first plate and the back surface of the second plate is located at aside portion of the heat exchange core, and the third corner hole of thefirst plate bypasses another end of the blocking member between thefront surface of the first plate and the back surface of the secondplate to communicate with the fourth corner hole of the first plate. 18.The plate heat exchanger according to claim 5, wherein a blocking memberis further arranged between the front surface of the first plate and theback surface of the second plate, the blocking member between the frontsurface of the first plate and the back surface of the second plate islocated between the third corner hole and the fourth corner hole of thefirst plate, one end of the blocking member between the front surface ofthe first plate and the back surface of the second plate is located at aside portion of the heat exchange core, and the third corner hole of thefirst plate bypasses another end of the blocking member between thefront surface of the first plate and the back surface of the secondplate to communicate with the fourth corner hole of the first plate. 19.The plate heat exchanger according to claim 11, wherein a blockingmember is further arranged between the front surface of the first plateand the back surface of the second plate, the blocking member betweenthe front surface of the first plate and the back surface of the secondplate is located between the third corner hole and the fourth cornerhole of the first plate, one end of the blocking member between thefront surface of the first plate and the back surface of the secondplate is located at a side portion of the heat exchange core, and thethird corner hole of the first plate bypasses another end of theblocking member between the front surface of the first plate and theback surface of the second plate to communicate with the fourth cornerhole of the first plate.
 20. The plate heat exchanger according to claim7, wherein a blocking member is further arranged between the frontsurface of the first plate and the back surface of the second plate, theblocking member between the front surface of the first plate and theback surface of the second plate is located between the third cornerhole and the fourth corner hole of the first plate, one end of theblocking member between the front surface of the first plate and theback surface of the second plate is located at a side portion of theheat exchange core, and the third corner hole of the first platebypasses another end of the blocking member between the front surface ofthe first plate and the back surface of the second plate to communicatewith the fourth corner hole of the first plate.